All earthquakes
3.2
weak
EARTHQUAKE DETAILS

M3.2 earthquake · 0 km South-East of Ovaro (UD)

10 years ago · 11 Nov 2015, 20:46

A weak earthquake, felt by some of the population. At only a few km deep the shaking is felt more sharply at the surface.

No. 10 of the month in ItalyStronger than 98% of Italian events in the past year

Where

0 km South-East of OvaroEarthquakes in the province of UdineEarthquakes in Friuli-Venezia Giulia

How far away could it be felt?

An estimate of how far people may have felt this quake.

  • up to ~15 km · felt only by some, at rest
    ≈ 21,000 people live in this area

The coloured rings on the map below show these distances.

Statistical estimate from the Italian intensity attenuation model (INGV): actual perception depends on geology, buildings and depth. Very shallow events can be felt locally even below the threshold.

Earthquake map

20 events
Magnitude:lightweakmoderatestrong

The energy released

How much energy this quake unleashed, translated into everyday comparisons.

952kgof TNT equivalent
4.0 lightning bolts
M3
×2 the energy of a magnitude 3 earthquake
M2this quakeM4

Each extra magnitude unit releases about 32 times more energy: an M5 is not "a bit stronger" than an M4 — it is a different league.

Energy estimated with the standard Gutenberg–Richter relation; an average lightning bolt ≈ 1 billion joules. Indicative values.

The race of the seismic waves

Two waves set off from the hypocentre: the faster P wave arrives first with a sharp jolt; the S wave carries the actual shaking.

P waves — the first sharp jolt (~6 km/s)S waves — the strongest shaking (~3.5 km/s)
t ≈ 33 s

Animation sped up ~6× compared to reality.

  • Udine
    56 km from the epicentre
    first tremor in ~10 s
    main shaking in ~16 s
  • Pordenone
    62 km from the epicentre
    first tremor in ~11 s
    main shaking in ~18 s
  • Treviso
    103 km from the epicentre
    first tremor in ~17 s
    main shaking in ~30 s
  • Bolzano
    114 km from the epicentre
    first tremor in ~19 s
    main shaking in ~33 s

Theoretical times with average crustal speeds: real values vary with geology. The gap between P and S waves is what earthquake early-warning systems rely on.

How deep it was born

10 km
shallow
1.1 times the height of Mount Everest

At only a few km deep the shaking is felt more sharply at the surface.

in line with the area average (~9 km)

For the same magnitude, a shallow earthquake is felt much more than a deep one: the energy starts closer to the surface.

What kind of quake is this?

Foreshock

In hindsight it was a foreshock: 10 years ago the same area had a stronger quake (M3.4). This can only be said after the fact — it was not predictable beforehand.

3.4
The mainshock
3 km North of Ampezzo
10 years ago · 21 Nov 2015, 12:52
Activity in the area right now (30 km radius)
1
last 24 hours
5
last 7 days
20
last 30 days
5 before14 after
this quake
Strongest of the sequence3.4

How often does it happen here?

about every ~3 months

Within 50 km of this epicentre, a magnitude ≥ 3 earthquake has occurred on average this often: 48 events in the last 12 years of the INGV catalogue.

An average computed on the recent past: it tells how used this area is to shaking, not when the next quake will come — earthquakes cannot be predicted.

The great earthquakes in this area's history

Almost a thousand years of catalogues: the strongest documented events within ~50 km.

19766.5
Friuli earthquake
6 May 1976 · 34 km from here
IX-XCompletely destructive: most buildings are destroyed.
15116.3
Friuli-Slovenia earthquake
26 March 1511 · 41 km from here
IXDestructive: many buildings partly or fully collapse.
19286.0
Carnia earthquake
27 March 1928 · 15 km from here
IXDestructive: many buildings partly or fully collapse.
17946.0
Prealpi Friulane earthquake
7 June 1794 · 20 km from here
IXDestructive: many buildings partly or fully collapse.

Source: Parametric Catalogue of Italian Earthquakes CPTI15 (INGV, CC BY 4.0).

The closest seismic structure

But-Chiarso

The epicentre lies about 12 km from But-Chiarso, one of the seismic structures mapped by INGV geologists.

estimated maximum magnitude 6.3between 1 and 9 km deep

Faults are mapped to build better and understand the territory: knowing them says nothing about when an earthquake will occur, which remains unpredictable. Source: DISS 3.3 (INGV, CC BY 4.0).

Other quakes in the area

1.1
2 km West of Ovaro
2 km West · 11 km
10 years ago
11 Nov 2015, 22:12
2.6
1 km South of Ovaro
0 km West · 10 km
10 years ago
11 Nov 2015, 22:20
0.7
2 km West of Ovaro
3 km West · 12 km
10 years ago
11 Nov 2015, 23:16
1.2
2 km West of Ovaro
2 km West · 11 km
10 years ago
11 Nov 2015, 09:42
1.1
3 km West of Ovaro
3 km West · 11 km
10 years ago
13 Nov 2015, 14:47
2.3
3 km West of Tramonti di Sopra
25 km South-West · 7 km
10 years ago
8 Nov 2015, 05:41
1.0
1 km North of Bordano
24 km South-East · 10 km
10 years ago
4 Nov 2015, 15:42
3.4
3 km North of Ampezzo
10 km West · 6 km
10 years ago
21 Nov 2015, 12:52
1.0
6 km West of Moggio Udinese
21 km East · 11 km
10 years ago
30 Oct 2015, 02:02
1.3
6 km North of Tramonti di Sopra
21 km South-West · 10 km
10 years ago
2 Dec 2015, 09:00

Data: INGV — National Institute of Geophysics and Volcanology (CC-BY 4.0)

Estimates computed by Meteare on INGV data (Gutenberg–Richter relation; Italian macroseismic intensity attenuation model).